GlaxoSmithKline welcomes European guidance

GlaxoSmithKline welcomes European guidance that stockpiling more than one antiviral would be useful in preparing for a flu pandemic

Issued — Monday 28 January 2008, London, UK

Both zanamivir ( Relenza ) and oseltamivir (Tamiflu) are recommended as candidates

GlaxoSmithKline (GSK) welcomes the new guidance from the European Medicines Agency (EMEA) on the use of antivirals during a flu pandemic and the recommendation that the availability of more than one antiviral would be useful in preparing for a flu pandemic.[1] The guidance has been revised in light of new evidence including emerging viral resistance.

The EMEA states that resistance has been observed more frequently, in particular amongst children, with increasing use of Tamiflu (oseltamivir). The EMEA suggests that the development of viral resistance may ‘substantially impact’ on oseltamivir’s clinical usefulness in the event of a pandemic.1 The updated EMEA guidance highlights that, in contrast, viral resistance to GSK’s Relenza (zanamivir) is extremely rare, and that some viral strains that are resistant to oseltamivir remain sensitive to zanamivir.

“The new EMEA guidance is a timely reminder that we need to constantly review our pandemic preparedness plans,” said Professor Albert Osterhaus, Professor of Virology, University of Rotterdam, Netherlands, and Chairman of the European Scientific Working Group on Influenza (ESWI), “The issue of viral resistance is of concern to influenza experts and I welcome the EMEA guidance that the availability of more than one antiviral would be useful. On reviewing pandemic strategies, Governments should seriously consider including more than one antiviral.”

The EMEA notes that resistance to zanamivir is extremely rareand that zanamivir has demonstrated efficacy in the treatment and prophylaxis of influenza.1,[2],[3] GSK believes therefore that it would be appropriate for zanamivir to be one of the antivirals stockpiled as part of flu pandemic preparations.

The new EMEA guidance, updated from its last review in October 2005, states that neuraminidase inhibitors are recommended for stockpiling and that both zanamivir and oseltamivir are ‘candidates’.

Zanamivir and oseltamivir are both antiviral medicines called neuraminidase inhibitors. Zanamivir, however, has a different structure to oseltamivir, and it has been suggested that this may explain why some viral strains remain sensitive to zanamivir when they have developed resistance to oseltamivir.2 The EMEA also noted that zanamivir’s mode of administration (inhalation via a Diskhaler TM) created limitations for use with very young children or people with chronic pulmonary disease.

“Antivirals are a key component of any flu pandemic response plan and the new EMEA guidance highlights that zanamivir has an important role to play in preparing for a potential pandemic,” said Eddie Gray, President of GSK Pharma Europe. “As the EMEA guidance states, an influenza pandemic is a major acute threat to public health and warrants concerted action for pandemic preparedness in Europe. As a manufacturer of both antivirals, and influenza vaccines, GSK is fully committed to supporting Governments in their plans to counter the threat of an influenza pandemic.”

GSK has invested €1.7 billion in expanding its global manufacturing and research capabilities in both vaccines and antivirals and in ensuring the continuity of critical business operations and processes, to safeguard the continued supply of critical medicines.

In June 2007, GSK committed to donate 50 million doses of its pre-pandemic vaccine to the World Health Organisation and to supply additional doses at tiered prices.

GlaxoSmithKline — one of the world’s leading research-based pharmaceutical and healthcare companies — is committed to improving the quality of human life by enabling people to do more, feel better and live longer.

For company information, visit GlaxoSmithKline at www.gsk.com [1]. Relenza is a registered trade mark of the GlaxoSmithKline group of companies

Notes to Editor

- Relenza (zanamivir) is indicated for treatment of both influenza A and B in adults and children (≥ 5 years) who present with symptoms typical of influenza when influenza is circulating in the community.

- Relenza is also indicated for post-exposure prophylaxis of influenza A and B in adults and children (≥ 5 years) following contact with a clinically diagnosed case in a household (see section 5.1 of SPC for children aged 5-11 years). In exceptional circumstances, Relenza may be considered for seasonal prophylaxis of influenza A and B during a community outbreak.

- Relenza is not a substitute for influenza vaccination. The appropriate use of Relenza for prevention of influenza should be determined on a case-by-case basis depending on the circumstances and the population requiring protection.

- The use of antivirals for the treatment and prevention of influenza should take into consideration official recommendations, the variability of epidemiology, and the impact of the disease in different geographical areas and patient populations.

Special warnings and precautions for use

Due to the limited number of patients with severe asthma or with other chronic respiratory disease, patients with unstable chronic illnesses or immunocompromised patients who have been treated, it has not been possible to demonstrate the efficacy and safety of Relenza in these groups. Due to limited and inconclusive data, the efficacy of Relenza in the prevention of influenza in the nursing home setting has not been demonstrated. The efficacy of zanamivir for the treatment of elderly patients ≥ 65 years has also not been established.

There have been very rare reports of patients being treated with Relenza who have experienced bronchospasm and/or decline in respiratory function which may be acute and/or serious. Some of these patients did not have any previous history of respiratory disease. Any patients experiencing such reactions should discontinue Relenza and seek medical evaluation immediately.

Due to the limited experience, patients with severe asthma require a careful consideration of the risk in relation to the expected benefit, and Relenza should not be administered unless close medical monitoring and appropriate clinical facilities are available in case of bronchoconstriction. In patients with persistent asthma or severe COPD, management of the underlying disease should be optimised during therapy with Relenza.

Should zanamivir be considered appropriate for patients with asthma or chronic obstructive pulmonary disease, the patient should be informed of the potential risk of bronchospasm with Relenza and should have a fast acting bronchodilator available. Patients on maintenance inhaled bronchodilating therapy should be advised to use their bronchodilators before taking Relenza (see section 4.2).